Builders: how not to drill your alu or carbon mast!

As a kitesurfer having waited 10 years for the hydrofoil to arrive, I’ve always thought it was a pity to drill through a mast to make cable pass through it and to drill for the nose as well.

And this is why:
1 - carbon HF owners must join and therefore 100% of the market can be retrofited, not only the alu HF
1 - easy installation ,
2 - easyy removal to wind propulsion mode without dammage,
3 - no money loss if you have to sell your HF to somebody not interested in the eFoil mode who won’t appreciate 2 or 3 holes in the alu mast.

Here is my solution.
I got the idea when looking at Robbie Edwards Youtube Channel:
A piece of masking tape to guide the cables from the board deck to the propulsion system (torpedo).

Then the light came while searching for wood floor skirting solutions on the internet:
PVC flexible skirting band, 10USD for 20 metres with 3M adhesive

As per the torpedo nose, a screwed cap joining both halves will be so much better !
Does anybody remember the AHD AFS1 nose system ? Yes, you will have to lock the nose with a safety system (needle, …)

AHD AFS1 screwed nose


Looks like a nice solution. The cables are OD5.5mm (3 cables) and maybe a hose for watercooling.

Will be a small bulge at the leading edge, but It should work just fine.

Like it. Was thinking about making a rigid front mast cover cable track before, shaped to blend in with the mast and easy to take on/off. Great if you want to use the same foil for kite foiling. 3x 8awg wires (possibly plus water tube) is quite the bulge. Maybe flat braided wires?

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Where can we find these wires and learn more?

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Thanks @Gobbla for making the idea real.

To go even further… along option #11 here: [Propulsion Type Overview - Wiki](//, it is possible to fit plenty of things in a mast skirt… Why not replacing the electric cables by a flexible shaft.
As most of them are 12in long (30cm) they can be combined: male 1/4in connector inside female 1/4in connector.
Thin cables are available, with or without angle cable adapters:
DEWALT DWARAFS Right Angle Flex Shaft, 12"
AUTOTOOLHOME 1/4 inch Magnetic Hex Flexible Drill Bit Extension Electric Screwdriver Quick Change with Angle Driver

Under investigation: what did Hydros use for their HY-41 prototype in their flexible link from motor to rear hydrofoil in 2014 ?

Hydros was bought by Enata Marine in 2016. In 2018, the HY-X concept from Hydros became the Foiler by Enata Marine.

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If I remember well, they had an hydraulic transmission, not very efficient

It’s not using a flexible shafts! They using two diesel engines to drive two electric motors.

Straight from their website:
“The FOILER has a hybrid diesel-electric propulsion.
The two inboard engines drive two generators providing the electrical power.
Two electrical torpedoes deliver the power that then propels the boat.”

That’s their prototype, and you can see on the video, the hydraulic lines going in the rear foils to the hydraulic transmission. I guess the overall efficiency wasn’t too good, that’s why they are going with a hybrid gen/elec
They tested this craft on the Geneva lake a few years back

The first prototype used indeed an hydraulic transmission. It was super noisy and not as efficient as an electric drive system.
Now, they are using 2 electric pods and the electricity comes from 2 motors (from BMW I think).

Six cables:
1 and 2 hydraulic power ?
3 and 4 hydraulic command (forward / reverse) ?
5 coolant ?
6 thin electric cables for probes

Maybe 3 & 4, is for the trim?

Has anyone here got more experience with hydraulics? I have none. I am wondering if you could have a 70mm hydraulic motor underwater and power it with 8mm diameter tubes from the board. Would be awesome.

New post created

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… IMHO it is quite possible to implement this solution at the 90° angle from mast to pod. However there might be a possible heat exchange issue between the three flat cables. Round is beautiful :grin:


@Gobbla Would you mind sharing details or files of how you implemented the wire duct. It’s always nice to see how others do it before I get distracted by my own horrible ideas :wink: For instance, I’d be curious to see if you used a key to connect the various 3D printed pieces together…or how the assembly/bolts were arranged in the nose…etc. Thanks. Trying to experience with this approach to ease myself into more builds in the future.

Hello, just back from holiday, I will try to share files this week.
I have test to pass cables in the mast, disappointing, no gain in electric consumption

This is sort of where I’m heading based on some stolen ideas :wink: Looking forward to seeing what you’ve been thinking.

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@mkefoil Nice work . You may also want to consider this design Flipsky/ Maytech 65161 propellers for sale - Props & Ducts -

Thanks @theone The prop end is where I still have the most to learn. I’m also pushing design parameters so that I can print everything myself here on my smaller print bed. So I’m going to have to go a little smaller in diameter to fit everything (especially if I don’t want to go open prop). The one in there is an enlarged version of something that started with the parametric design I found here. I’ll go through the whole java prop process and see what I come up with there that fits. Hopefully finding a decent compromise.